White House insiders say Chuck Hagel’s departure as defense secretary signifies a change of direction for President Barack Obama’s national security team.

The officials, speaking anonymously to The New York Times, said Obama decided to remove Hagel, 68 and the only Republican in his Cabinet, because the threat from the Islamic State in Iraq and Syria requires different talents and experience than Hagel was brought on to employ.

That might be a valid observation. Hagel’s most notable accomplishments included the withdrawal of U.S. forces in Afghanistan and shrinking the military budget under sequestration.

But Hagel’s sudden exit raises a significant question: If he doesn’t have the capacity to quell a militant Islamic caliphate like ISIS, then who does?

In a January interview, Obama downplayed the emerging ISIS threat: “The analogy we use around here sometimes,” he said, “and I think is accurate, is if a jayvee team puts on Lakers uniforms that doesn’t make them Kobe Bryant.”

Six months later, ISIS had disproved any notion of a junior varsity label. Its forces had overrun the Iraqi cities of Mosul and Tikrit and were threatening Baghdad. With hundreds of square miles under their control, ISIS leaders declared themselves an independent Islamic state under Shariah law.

Since August, ISIS has beheaded three American hostages and two others from Great Britain.

It was Hagel who sounded the alarm — and contradicted his boss — at a news conference in August, calling ISIS “as sophisticated and well-funded as any group that we have seen.” Hagel added, “They’re beyond just a terrorist group. They marry ideology, a sophistication of strategic and tactical military prowess. They are tremendously well-funded. Oh, this is beyond anything that we’ve seen. So we must prepare for everything.”

Hagel’s comments did not sit well with administration officials, who later called them unhelpful. Yet despite the contradiction, Hagel managed to keep his job — until after the November elections.

Republicans in November strengthened their hold on the House of Representatives and gained control of the Senate. The election was widely regarded as a measure of dissatisfaction not only with government inaction but specifically with the White House’s inability to lead.

The White House knows by now it is not dealing with the junior varsity; targeted bombings since August have slowed but not stopped its advance. More than 3,000 U.S. troops are being deployed to Iraq to act as advisers to Iraqi troops. The U.S. continues to court potential allies in the fight against the caliphate.

But more must be done, and Hagel’s departure confirms that Obama knows more must be done.

The two remaining questions loom large: What more will be done, and who will be in charge?